<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        .box{
            margin: 100px auto;
            width: 250px;
            /* background-color: pink; */
        }
        
        .box li{
            float: left;
            list-style: none;
            width: 24px;
            height: 24px;
            margin: 15px;
            background: url(images/sprite.png) no-repeat;
        }

    </style>
</head>
<body>
    <div class="box">
        <ul>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
        </ul>
    </div>
    <script>
        var lis = document.querySelectorAll('li');
        for(var i = 0; i < lis.length; i++) {
            var index = i * 44;
            lis[i].style.backgroundPosition = '0 -' + index + 'px';
        }
    </script>
</body>
</html>